A nitronyl nitroxide and its two 1D chain Cu–Tb complexes: synthesis, structures, and magnetic properties†
Abstract
A new nitronyl nitroxide, namely NIT-Ph-p-OCH2trz (1), and two types of one-chain Cu–Tb complexes, namely [TbCu(hfac)5NIT-Ph-p-OCH2trz·0.5C6H14]n (2a) and [LnCu(hfac)5NIT-Ph-p-OCH2trz]n (2b) (NIT-Ph-p-OCH2trz = 2-(4-((1H-1,2,4-triazol-1-yl)methoxy)phenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; hfac = hexafluoroacetylacetonate), have been successfully synthesized simultaneously through reacting nitronyl nitroxide radical NIT-Ph-p-OCH2trz with Cu(hfac)2 and Ln(hfac)3, and the molecular structures have been elucidated via single-crystal X-ray structural analysis. 2a features a ‘ladder-like’ chain structure, while 2b displays a linear chain structure built up by Ln(hfac)3 units bridged with the NO groups of radical ligands. The additional Cu(II) ions are coordinated to the nitrogen atoms of the triazole units. Nonzero out-of-phase signals are observed for the Tb derivatives (2a and 2b) and they exhibit frequency-dependent out-of-phase signals indicating a single-chain magnet behavior.